Lead sulfide, also known as galena, occurs naturally on planet Earth. It is an important ore of lead, and forms dull, grayish, cubical crystals of varying size. It is also a natural semiconductor, and as such was vital in the early days of radio, when a single galena crystal was used as a 'detector' for radio waves.

Lead sulfide crystals are also a Cybertronian food product, and are apparently delicious when combined with savory mercury sauce and flavorful iron filings as garnish for a tasty robot. They are, of course, poisonous and quite inedible for humans. It should be noted that crystals found on Femax emit a greenish glow in the visible spectrum; this may indicate that they are formed from an unknown radioactive lead isotope.

Lead sulfide additive appears to act as an anti-allergy remedy for some Transformers. Lightspeed must take some with his fuel or break out with a rust rash and other troubling symptoms.

Entrees

Cesium salami and beryllium baloney (maybe)

Cesium salami and beryllium baloney are referenced by the DinobotsGrimlock and Slag while they are wandering the surface of Quintessa trying to locate their comrades. It is unclear whether they are actual Cybertronian foods or merely a figure of speech. The Transformers: The Movie